The present invention relates to generally circular seal configurations of the type used for sealing the annular clearance between an inner cylindrical member and an outer cylindrical member and, more specifically, to a circular seal of the type used to seal the annular clearance between a cylinder internal diameter and a piston rod outer diameter.
Circular, piston type seal constructions are used in many environments where it is desirable to seal off the clearance which exists between an inner cylindrical member, such as the outer diameter of a piston rod, and an outer cylindrical member. In downhole tools of the type used in the oil industry, such as packers, liner hangers, and the like, such circular seals are used to provide a fluid seal, as between an inner mandrel and an outer tubular member in a well tool. When pressure is applied to the annular space between the tubular mandrel and outer tubular member, the circular seals seats to that, for instance, a cone element can be hydraulically driven in the direction of a slip element to cause outward radial movement of the slips to grip a surrounding casing in the well bore.
Seal configurations in the well environment are typically subjected to pressures in the range of 2,000 psi at 200.degree.-300.degree. F. and are subject to the destructive effects of contaminants such as drilling fluids, reservoir fluids and hydrogen sulfide contamination.
A need exists for a circular seal for sealing the annular clearance between an inner cylindrical member and an outer cylindrical member which can withstand pressures in the range of 2,000-7,500 psi and greater at temperatures in the range of 300.degree.-400.degree. F. or greater.
There exists a need for such a seal design which can withstand the effects of hydrogen sulfide and other contaminants of the type commonly encountered in wellbore operations.